Field of the Invention
The present invention relates to communication technology for performing communication of image data.
Description of the Related Art
A method has been known in which only a part of an overall region of a video captured by an image capturing apparatus is transmitted. JP 5544426 B2 discloses that a server 1 specifies a viewing region Av in an overall region Aw based on viewpoint movement information acquired from a client 2, and transmits a viewing region video corresponding to the viewing region Av to the client 2. By doing the above procedure, the client 2 can display the viewing region Av on a display screen.
However, there has been a risk that image data corresponding to an image to be displayed on a display screen is not transmitted.
For example, there may be a case where a user desires display of not only an image of a region of interest (ROI) in an overall region but also an image of a region surrounding the region of interest. When only image data of the region of interest is transmitted from other communication apparatus in such a case, the image of the surrounding region cannot be displayed.
In addition, for example, there may be a case where when a region of interest in an overall region in a moving image is being displayed on a display screen, a user performs an operation to change the region of interest to be displayed on the display screen. When only an image of the region of interest before change has been acquired in such a case, an image to be displayed and an image acquired from other apparatus do not match each other. If a user performs an operation to change a region of interest and then performs a process for acquiring a moving image of the changed region of interest, there may be a possibility that it takes some time to start displaying the moving image of the changed region of interest.
On the other hand, when employing a method in which image data corresponding to an overall region is always transmitted, or a method in which image data corresponding to a surrounding region is always transmitted, a load in proportion to a communication data amount is increased. Examples of the load in proportion to a communication data amount include a load on transmission of image data by a transmitting apparatus, a load on reception or a decoding process of image data by a receiving apparatus, and a load on a communication network.